The council’s infrastructure committee on Tuesday heard more than 10 major projects, both government and private, are underway in the city centre this month and will continue through most of the year.

Queen’s Wharf, Cross River Rail, new state schools, Waterfront Brisbane, the Kangaroo Point green bridge, Brisbane Metro and the new performing arts venue in South Bank were some of the construction projects flagged.

Multiple other private developments, such as skyscraper office and apartment towers, are also being constructed this year in the CBD.

Traffic modelling completed by the council, using 2018 traffic levels as a baseline, found the sheer number and size of the projects, many of which will need temporary lane closures or diversions, meant travel times could increase.

There could be “extended queues” onto the Riverside Expressway through to the Captain Cook Bridge and Coronation Drive, a report presented to councillors said.

Buses through the city could also be delayed, and motorists are predicted to change their driving habits to avoid the worst of the congestion points in a “substantial redistribution of traffic”.

It follows an RACQ assessment of Brisbane traffic that found people were still avoiding public transport and opting to drive, which had led to congestion worse than pre-COVID levels.

RACQ spokesperson Lauren Ritchie told ABC News on Tuesday the city was now seeing several peak hours daily and “alarming” congestion rates.

The council’s manager of transport planning and operations, Marie Gales, said staff had assessed travel times and traffic volumes to clarify how so many construction projects needing road space and closures could impact the CBD.

“[For utility service upgrades], we don’t always get a lot of notice on these, but sometimes they actually take the opportunity to do upgrades where other works are going on, and then with private developments you have to be a bit agile and react to them,” she said.

“We have been doing a lot of work with developers in terms of helping them understand that road space isn’t necessarily always available.”

She cited one development in Ann Street that wanted to close a lane for three years, which was rejected, and the developers adjusted their project to fit.

Travel time modelling completed in October 2020, based on 2018 traffic levels, found that the afternoon peak on Edward Street could blow out by nearly 200 seconds under one scenario.

That scenario would become likely once Victoria Bridge was closed, the CityLink Cycleway came online and Brisbane Metro work began, the report said.

Commuters on Elizabeth Street and Edward Street in the afternoon could also see a 140-second increase under that scenario.

Since the closure of Victoria Bridge on January 24, traffic on Elizabeth Street has declined while Roma Street traffic has increased.

The council is now taking on the task of coordinating all of the projects to manage congestion impacts.

A combined traffic management plan has already been developed to manage the congestion in South Brisbane around Grey Street, where the new performing arts centre, the Neville Bonner Bridge, and Brisbane Metro are all working at the same time.

Staff have also set up working groups with state government departments to manage the conflicting needs of each project and ensure congestion is kept to a minimum, Gales said.

“We were seeing all of these projects coming online, so … we reached out to the state and we’ve set up a steering group, and then a traffic coordinations group and an approvals group, with multiple state departments as well as ourselves,” she said.

“We tend to lead all the coordination because we see what’s coming better than the state departments. They see what’s in their little bit.”

– ABC / Lucy Stone